Enzyme activity and temperature

What is the role of enzymes in metabolic reactions?

Enzymes act as biological catalysts, speeding up metabolic reactions without being used up.

How does temperature affect enzyme function and the shape of an enzyme’s action site?

As temperature increases, enzyme activity increases until the optimum temperature is reached. Above this temperature, the enzyme is denatured

What does it mean when an enzyme is denatured?

Its active site changes or disappears, meaning the substrate can no longer fit into it, so the enzyme can no longer catalyse the reaction properly

Describe the effect of low and high temperatures on enzyme activity

Low temperature slows enzyme reactivity because the particles have less kinetic energy and collide less often. High temperature increases the speed up to the point of optimum temperature; after this the enzyme denatures

What is the aim of the enzyme temperature practical?

To investigate how temperature affects the rate of enzyme activity

What is the independent variable in the enzyme temperature practical?

The temperature of the enzyme reaction

What is the dependent variable in the enzyme temperature practical?

The rate of enzyme activity (how quickly the reaction occurs

What variables should be controlled in the enzyme temperature practical?

pH, enzyme concentration, substrate concentration, and volume of solutions

How is the enzyme temperature practical carried out?

The enzyme and substrate are placed at different temperatures, mixed together, and the rate of reaction is measured.

What happens to enzyme activity as temperature increases up to the optimum temperature?

Enzyme activity increases because particles have more kinetic energy and collide more frequently.

What is the optimum temperature?

The temperature at which an enzyme works at its maximum rate

What happens when the temperature rises above the optimum temperature?

The enzyme denatures and its active site changes shape.

Why does enzyme activity decrease above the optimum temperature?

The substrate can no longer fit into the altered active site